1. Field of the Invention
The present invention relates to polymer colloids, and methods for cytosolic delivery of materials such as luminescent nanoparticles.
2. Related Art
Luminescent nanocrystals hold great potential for bioimaging because of their exceptional optical properties, but their use in live cells has been limited. One of the major challenges in applying luminescent nanocrystals as probes for cellular imaging has been the difficulty of using them inside of live cells. While nanocrystals have exceptional optical properties and hold great potential as probes of these pathways, they have difficulty in reaching subcellular targets. Nanocrystals are typically taken up by cells via endocytosis and the large majority remains trapped in endosomes and vesicles, unable to reach the cytosol. Staining patterns are characteristically punctuate and often bright enough to obscure nanocrystal luminescence elsewhere.
This vesicular sequestration is persistent and precludes nanocrystals from reaching intracellular targets. Microinjection and other techniques have been used as an endgame around this problem; however, these processes are labor intensive, low throughput and frequently kill the treated cell. Molecular engineering of nanocrystal surface passivation, via TAT or other cell penetrating peptide motifs, has also not afforded an efficient mechanism of release from endosomes.